[Plugin: WP-FB-comments] Question regarding comments

Will this plug in work if I post the link manually without letting the plug in post to my wall? For instance; I like to type a little line or two about the link when I post it to my Facebook page. Then people usually leave comments on the Facebook page and on the wordpress site itself. I want for people who leave comments on Facebook to have their comments merge with the blog post on wordpress, and vis versa…so it’s like one conversation. (I was also curious how quick the comments are merged. If someone leave a comment at say 1 pm on Facebook, how long will it take to show up in wordpress, and vis versa?)

Also if I post the link twice at different times of the day, will it merge both instances to the blog?

One last thing, does this plug in only work with new posts published once the plug in was installed, or can it go retroactively back and merge Facebook conversations on past posts?

Thanks a lot.

https://www.ads-software.com/extend/plugins/wp-fb-comments/